Evidence points to man-made disaster

Investigators and residents have picked through the battered New Orleans levee system's breaches, churned-up soil and bent sheet pile in the 100 days since Hurricane Katrina struck, they have uncovered mounting evidence that human error played a major role in the flood that devastated the city.

Floodwall breaches linked to design flaws inundated parts of the city that otherwise would have stayed dry, turning neighborhoods into death traps and causing massive damage. In other areas, poorly engineered gaps and erosion of weak construction materials accelerated and deepened flooding already under way, hampering rescue efforts in the wake of the storm.

These problems turned an already deadly disaster into a wider man-made catastrophe and have made rebuilding and resettlement into far tougher and more expensive challenges.

That's the picture that emerges from investigations of the levee system by teams sponsored by the state government, the American Society of Civil Engineers and the National Science Foundation, as well as from dozens of interviews with local residents, officials and engineers.

Experts say the New Orleans flood of 2005 should join the space shuttle explosions and the sinking of the Titanic on history's list of ill-fated disasters attributable to human mistakes.